Web conveyor apparatus

ABSTRACT

Web conveyor apparatus for use in feeding a generally vertically oriented heated web of thermoplastic material to a container molding station wherein there is provided a plurality of conveyor clip devices which are mounted for movement along a predetermined path immediately above the upper margin of the web of thermoplastic material, each conveyor clip device including positive gripping and release features which assure accurate predetermined feeding of the web.

United States Patent UN NH l ,86l .282 5/1932 Nelson Walter C. DienerOak Park, Ill.

Nov. 12, 1969 Aug. 10, I97 I Illinois Tool Works Inc. Chicago, Ill.

Inventor Appl. No. Filed Patented Assignee was conveyor: APPARATUS 4Claims, 3 Drawing Figs.

[15. Cl 226/173 B651! 17/34 FieltlolSearch 226/170,

References Cited UNITED STATES PATENTS 3,029,007 4/ l 962 Hepner t.

Primary ExaminerAllen N. Knowles Auarneys-Robert W. Beart, MichaelKovac, Barry L. Clark and Jack R. Halvorsen AACT: Web conveyor apparatusfor use in feeding a generally vertically oriented heated web ofthermoplastic material to a container molding station wherein there isprovided a plurality of conveyor clip devices which are mounted formovement along a predetennined path immediately above the upper marginof the web of thermoplastic material, each conveyor clip deviceincluding positive gripping and release features which assure accuratepredetermined feeding of the web.

WEB CONVEYOR APPARATUS This application is a companion to patentapplication Ser. No. 845,270, filed July 28, 1969, in the name of BryantEdwards and assigned to the same assignee as the present application.Reference to this companion Edwards application is made throughout thespecification hereof in order to set forth the preferred environment inwhich the instant invention preferably operates.

As disclosed in the companion Edwards application, a continuous motioncontainer-molding machine and method is provided with cooperating moldswhich operate upon heated thermoplastic sheet or web material to formdisposable containers. In general, the continuous molding machine ormethod includes the steps or means for feeding a heated thermoplasticweb to at least one pair of continuously rotating cooperating molds,simultaneously attaching the web to the molds for predetermined,coincidental movement therewith and clamping off a predetenninedmaterial area from the remainder of the web, and then forming containersfrom the predetermined material area when attached to the cooperatingmolds. a i Y in a method or machine of the type described, the heatedthermoplastic web must be generally vertically oriented or positioned asit is fed from the supply roll to the continuously rotating cooperatingmolds at the molding station. For this purpose, the present inventioncontemplates a web conveyor apparatus which functions in the desiredmanner as will be discussed in detail below.

it is an object of the present invention to provide a web conveyorapparatus including one or more conveyor clip devices which assurespredetermined feeding of a generally vertically oriented or positionedheated thermoplastic web.

Another object of the present invention is the provision of conveyorclip devices which positively grip and release a heated thermoplasticweb for accurate, predetermined feeding thereof.

These and other objects and advantages of the present invention areattained by the provision of a conveyor clip device which is used forfeeding a generally vertically oriented heated web of thermoplasticmaterial to a container-molding station and including means for mountingthe conveyor clip device immediately above the upper margin of the webfor movement therealong, a pair of spring-biased clamping elementsdepending from the mounting means for engaging limited areas on oppositesurfaces of the web along the upper margin thereof, and means forspreading the clamping elements after predetermined feeding of the web.The present invention also contemplates the use of a plurality ofsimilarly configured conveyor clip devices of the type described abovein conjunction with an endless mechanism upon which the conveyor elipdevices are mounted in spaced relationship to one another.

Reference is now made to the drawing wherein:

FIG. 1 is a fragmentary side elevational view of a web con= veyorapparatus, including a plurality of conveyor clip devices, which isconstructed in accordance with the teachings of the present invention,the apparatus being shown as it delivers a heated web of material to acontainer-molding stu= tion and the subsequent disengagement of theconveyor clip devices after predetermined feeding of the web;

FIG. 2 is an enlarged partial cievational and sectional view of a webconvey or clip device as viewed along line 2=2 of FIG. 1; and

FIG. 3 is also an enlarged partial elevationai and sectional view asviewed along line 3-3 of FlG. 1 and illustrating in full lines theclamping of the heated web material, and in dotted lines the subsequentrelease thereof.

The web conveyor apparatus of the present invention in= cludes a drivenendless chain 12 or other equivalent mechanism and a plurality ofspaced, web conveyor clip devices 14 which are arranged to grip a heatedweb of ther moplastic material 16 along the upper margin thereof forpredetermined feeding of the web 16 to a container-molding stationpartially shown at 18. Reference is made to the aforesaid Edwardsapplication for a specific description of the preferred form ofcontainer-molding station with which the which is being fed from asupply roll (not shown to the container-molding station 18. The endlesschain 12 or other equivalent mechanism may be driven by sprocket wheelsat opposite ends thereof such as the sprocket wheel 20 illustrated inFIG. 1 of the drawing. The sprocket wheel 20 with a specially configuredtooth formation may also be used as will be described below in openingand/or closing the web conveyor clip devices 14.

Each of the web conveyor clip means 14 is arranged to grip in sequentialfashion the web 16 of material adjacent the supply roll (not shown) andcarry or feed the web 16 to the container-molding station 18 whereuponthe conveyor clip devices are disengaged from the web 16 and thenreturned to the position where the web conveyor clip devices 14 canagain engage and grip the web 16. it is important to note that each ofthe web conveyor clip devices 14 are designed to engage the web 16, asbest seen in FIGS. 1 and 3 of the drawing, along limited upper marginalareas of the vertically oriented web 16 in a manner so as not tointerfere with any of the clamps and molds of the continuous-moldingstation 18.

Each of the web conveyor clip means 14 is provided with a pair offree-rotating rollers 22, 24 which are mounted on opposite sides of theendless chain 12. Each pair of rollers 22, 24 are mounted in a closed,endless track (not shown) to prevent sagging of the endless chain 12.The opposed pairs of rollers 22, 24 are mounted in the plane of theendless chain 12 and are supported on bushings 26, 28 which are mountedat opposite ends of the shafts 30. Fastening means in the form of aC-retaining ring 32 or the like prevents lateral movement anddisassembly of the rollers 22, 24 relative to the shafts 30. As bestseen in FIG. 2 of the drawing, the shafts 30 extend through the endlesschain 12 and thus are carried thereby along with the associated pairs ofrollers 22, 24.

For clamping the web 16 along the upper margin thereof, a pair ofspring-biased clamping elements 34, 36 are provided. The clampingelements 34, 36 are configured and mounted relative to the endless chain12 to provide upper sections 38, 40 respectively which are generallyparallel to each other, middle body sections 42, 44 respectively whichgenerally have a scar spring shape, and a pair of lower sections 46, 48which function to clamp the web 16 as will be presently described. Theupper body sections 36, 40 of the clamping elements 34, 36 respectivelyhave suitably aligned upper and lower openings for receiving the pairsof shafts 30 and the single lower shaft 50. Two pairs of retainingplates 52, 54 are mounted on the pair of shafts 30 and shaft 50 onopposite sides of the upper sections 38, 40 respectively of the clampingelements 34, 36. Nuts 56 thrcadably associated with the shaft 50 engagethe outer plate of each of the pairs of retaining plates 52, 54 andclamp the upper sections 38, 40 against the inner plates of the pairs ofretaining plates 52, 5d, the in inner plate in each pair of retainingplates 52, S4, in turn, being sup ported by the endless chain I: alongouter faces thereof as indicated in F165. 2, 3 of the drawing. Thisprovides a stable and secure mounting for each clamping element 34, 36relative to the endless chain 12.

The clamping elements 34, 36, when mounted to the endless chain 12 inthe manner just described, enable the sear spring=shaped middle bodysections 42, 44 respectively to maintain the lower clamping sections 46,48 in a closed position as best illustrated in FIG. 2 of the drawing.Thus, the clamping elements 34, 36 are normally spring biased to aclosed position to assure gripping of the web 16 for the unimpcdcddelivery thereof.

in order to open the lower clamping sections 46, 48 of the clampingplates 34, 36 respectively to permit the engagement and disengagementwith respect to a web 16, there is provided a plunger element 60associated with each web conveyor clip means 14. Each plunger element 60includes a head portion 62 and an elongated shank 64 having a verticalslot 66 therein for mounting the plunger 60 relative to the shaft 50while permitting limited vertical movement thereof, and an enlarged footsection 68 with integral wing elements 70, 72 which are mounted inlongitudinal openings 74, 76 of the sear springshaped middle bodysections 42, 44. The limited vertical movement of each plunger 66,permitted by the vertical slot 66, is complemented by the sphericalshape on the lower face of the enlarged foot section 68 which, when theplunger 60 is depressed, moves the downwardly and inwardly taperingportions of the middle body sections 42, 44 apart from one another toopen up the clamping sections 46, 48 as is illustrated in FIG. 3 of thedrawing. The wing elements 70, 72 move within the longitudinal openings74, 76 when this occurs, thereby assuring stability to the plungerelement 60 during its movement. Upward movement of a plunger element 60will then cause the sear spring-shaped middle body section 42, 44 tomove the clamping sections 46, 48 respectively to their normally clampedor closed position. The plunger elements 60 are depressed adjacent thesupply roll (not shown) in order to permit the web conveyor clips 14 togrip the web 16 adjacent the upper margin thereof and also after the web16 has been clamped to the container-molding station 18 by opposedcircumferential web-clamping means 78, 80, only partially shown. Whileany suitable means may be employed for this purpose, it has been foundthat a sprocket wheel 20 with a spe cially configured tooth formation 82is very effective in engaging the heads 62 of the plunger elements 60and depressing them at the desired moment.

Although a specific embodiment of the present invention has been shownand described, it is with full awareness that many modifications thereofin addition to those specifically mentioned are possible. The invention,therefore, is not to be restricted except in so far as is necessitatedby the prior art and by the spirit of the appended claims.

lclaim:

l. A conveyor clip device for use in feeding a generally verticallyoriented heated web of thermoplastic material to a container-moldingstation comprising means for mounting said conveyor clip deviceimmediately above the upper margin of said web for movement therealong,a pair of spring-biased clamping elements depending from said mountingmeans and having cooperating lower tip portions for engaging limitedareas on opposite surfaces of said web along the upper margin thereof,spreader means carried on said mounting means for limited reciprocatingmovement and positioned between and engaging said pair of clampingelements above said tip portions, whereby said tip portions are openedand closed responsive to reciprocating movement of said spreader means.

2. A conveyor clip device as defined in claim 1, wherein saidspring-biased clamping elements immediately above said tip portions areformed to diverge upwardly, and the lower end of said spreader meanscomprising a head portion formed to have downward converging surfacescooperating with the upwardly diverging portions of said spring-biasedclamping elements so that said tip portions are opened and closedresponsive to reciprocating movement of said spreader means.

3. A conveyor clip device as defined in claim 2, wherein the upwardlydiverging portions of said spring-biased elements are provided withvertically extending slots therethrough, and said head portion of saidspreader means having wing elements mounted thereon and positionedwithin said slots for reciprocating movement within said slotsresponsive to reciprocating movement of said spreader means.

4. In combination, a plurality of conveyor clip devices as defined inclaim I, an endless mechanism for carrying said devices, said mountingmeans of said devices carrying said devices on said endless mechanism ina spaced predetermined relationship to each other, and means for movingsaid spreader means.

1. A conveyor clip device for use in feeding a generally verticallyoriented heated web of thermoplastic material to a container-moldingstation comprising means for mounting said conveyor clip deviceimmediately above the upper margin of said web for movement therealong,a pair of spring-biased clamping elements depending from said mountingmeans and having cooperating lower tip portions for engaging limitedareas on opposite surfaces of said web along the upper margin thereof,spreader means carried on said mounting means for limited reciprocatingmovement and positioned between and engaging said pair of clampingelements Above said tip portions, whereby said tip portions are openedand closed responsive to reciprocating movement of said spreader means.2. A conveyor clip device as defined in claim 1, wherein saidspring-biased clamping elements immediately above said tip portions areformed to diverge upwardly, and the lower end of said spreader meanscomprising a head portion formed to have downward converging surfacescooperating with the upwardly diverging portions of said spring-biasedclamping elements so that said tip portions are opened and closedresponsive to reciprocating movement of said spreader means.
 3. Aconveyor clip device as defined in claim 2, wherein the upwardlydiverging portions of said spring-biased elements are provided withvertically extending slots therethrough, and said head portion of saidspreader means having wing elements mounted thereon and positionedwithin said slots for reciprocating movement within said slotsresponsive to reciprocating movement of said spreader means.
 4. Incombination, a plurality of conveyor clip devices as defined in claim 1,an endless mechanism for carrying said devices, said mounting means ofsaid devices carrying said devices on said endless mechanism in a spacedpredetermined relationship to each other, and means for moving saidspreader means.